Flow velocity estimation and ultrasound systems for flow velocity estimation

Abstract

Systems and methods for measuring flow velocities, including ultrasound systems, are provided. A Doppler angle between a direction of ultrasound signals and an axis of a flow may be estimated to improve the accuracy of the flow velocity estimation that is based on Doppler effects. A sensor may be mounted on or in an ultrasound probe to obtain a reference orientation of the ultrasound probe and an orientation of the ultrasound probe relative to the reference orientation when the ultrasound probe is moved to other positions. The Doppler angle may be estimated based on the orientation of the ultrasound probe.

What is claimed is: 
     
         1 . A method for measuring a flow velocity, the method comprising:
 transmitting ultrasound signals to a target object, the ultrasound signals being emitted from an ultrasound signal transmitter in a ultrasound device;   detecting ultrasound echo signals resulting from the ultrasound signals emitted to the target object, the ultrasound echo signals being reflective of a flow within the target object;   detecting, by a sensor, an orientation of the ultrasound device relative to a reference orientation, the reference orientation comprising a Doppler angle of about 90 degrees;   estimating a Doppler angle between a primary direction of the ultrasound signals and an axis of the flow within the target object based on at least the orientation of the ultrasound device; and   estimating the flow velocity of the flow within the target object based on at least an estimated Doppler angle.   
     
     
         2 . The method of  claim 1 , wherein the reference orientation is determined based on a Doppler image of a projected flow velocity on the primary direction of the ultrasound signals. 
     
     
         3 . The method of  claim 2 , wherein the projected flow velocity is approximately zero when the ultrasound device is placed at the reference orientation. 
     
     
         4 . The method of  claim 1 , wherein the sensor is mounted on or in the ultrasound device for detecting the orientation of the ultrasound device. 
     
     
         5 . The method of  claim 1 , wherein a summation of the estimated Doppler angle and the orientation of the ultrasound device is about 90 degrees. 
     
     
         6 . The method of  claim 1 , further comprising performing transmission focusing and reception focusing, by using a beam former, based on relative positions between the target object and the ultrasound device. 
     
     
         7 . The method of  claim 1 , wherein a chip integrated in an ultrasound system is configured to estimate the flow velocity based on at least an estimated Doppler angle. 
     
     
         8 . The method of  claim 1 , wherein the sensor comprises one of an accelerometer, a gyroscope, a compass, a GPS receiver, and a camera. 
     
     
         9 . An ultrasound system for measuring a flow velocity, comprising:
 an ultrasound device operable to transmit ultrasound signals to a target object and to detect ultrasound echo signals from the target object, the ultrasound echo signals being reflective of a flow within the target object;   a sensor for detecting an orientation of the ultrasound device relative to a reference orientation, the reference orientation comprising a Doppler angle of about 90 degrees; and   a processing device coupled with the ultrasound device for processing the ultrasound signals and the ultrasound echo signals, the processing device configured to:
 estimate a Doppler angle between a primary direction of the ultrasound signals and an axis of the flow within the target object based on at least the orientation of the ultrasound device; and 
 estimate the flow velocity of the flow within the target object based on at least an estimated Doppler angle. 
   
     
     
         10 . The ultrasound system of  claim 9 , wherein the reference orientation is determined based on a Doppler image of a projected flow velocity on the primary direction of the ultrasound signals. 
     
     
         11 . The ultrasound system of  claim 10 , wherein the projected flow velocity is approximately zero when the ultrasound device is placed at the reference orientation. 
     
     
         12 . The ultrasound system of  claim 9 , wherein the sensor is mounted on or in the ultrasound device for detecting the orientation of the ultrasound device. 
     
     
         13 . The ultrasound system of  claim 9 , wherein a summation of the estimated Doppler angle and the orientation of the ultrasound device is about 90 degrees. 
     
     
         14 . The ultrasound system of  claim 9 , wherein the ultrasound device includes a beam former to perform transmission focusing and reception focusing based on relative positions between the target object and the ultrasound device. 
     
     
         15 . The ultrasound system of  claim 9 , wherein a chip integrated in the ultrasound system is configured to estimate the flow velocity based on at least an estimated Doppler angle. 
     
     
         16 . The ultrasound system of  claim 9 , wherein the sensor comprises one of an accelerometer, a gyroscope, a compass, a GPS receiver, and a camera.